Someone doesn't know how to wire up O2 sensors, or have any basic understanding of how electrical circuits work- assuming all 3 wires were twisted together.
If you have to purchase new O2 sensors, pay the extra like $10 for an OEM. In fact, check with Village Ford
, one of our vendors, and see what his price is on Motorcraft sensors for your car. It might be cheaper than you think. Supposedly we get employee discounts through them. We have had more than a few people blame problems on Bosch O2 sensors.